Guaiaci Lignum, B.P., Guaiacum Wood. Guaiaci Resina, B.P., Guaiacum Resin.
GUAIACI LIGNUM, B.P.
Guaiacum wood is obtained from Guaiacum officinale, Linn., and G. sanctum, Linn. (N.O. Zygophyllaceae), evergreen trees, the former a native of the West Indian Islands and north coast of South America, the latter indigenous to South Florida and the Bahaillas. The trees are felled, stripped of their bark, and cut into logs or billets for export. The heart wood is dark greenish-brown in colour, dense, hard, and heavier than water. It has a slightly acrid taste, and when heated gives off an aromatic odour. The sap wood is much paler in colour than the heart wood, and should not be present in appreciable quantity. The drug yields about 1.5 per cent. of ash.
Constituents.—The drug contains from 20 to 25 per cent. of resin, consisting of guaiaretic, guaiaconic, and guaiacic acids; to guaiaconic acid is due the blue colouration with oxidising agents (compare Guaiaci Resina). It also contains two bodies, guaiacsaponic acid and guaiacsaponin, belonging to the class of saponins, as well as a substance resembling gutta percha, termed guaiaguttin.
Uses.—Guaiacum wood is not much used in medicine, the resin being preferred.
GUAIACI RESINA, B.P.
Guaicum resin (Guaiacum, U.S.P.; Guaiac) is obtained from the stem of Guaiacum officinale, Linn., or of Guaiacum sanctum, Linn. (N.O. Zygophyllaceae). Most of the resin found in commerce is obtained by raising one end of a log of the wood and firing it; the heat melts the resin, which flows out of a hole or groove cut in the other end and is caught in potsherds or vessels. A small quantity is imported in large tears the size of walnuts or even larger. The resin may occur in rounded or ovoid tears, or in large blocks, the latter being the usual form. It breaks easily with a clean glassy fracture, the thin pieces being transparent and exhibiting a colour varying from yellowish-green to reddish-brown. The powder is grey, but becomes green on exposure to light and air, and should, therefore, be preserved in well-stoppered, dark amber-coloured bottles. It has a slightly acrid taste, and, when warmed, a balsamic odour. Block guaiacum resin often contains considerable quantities of woody debris, etc. Good samples yield less than 8 per cent. of substances insoluble in alcohol, and less than 3 per cent. of ash. Tear resin yields about 2 per cent. of foreign substances and 1 per cent. of ash, and is therefore to be preferred to the block, but does not reach the market in sufficient quantity to supply the demand.
Constituents.—The chief constituents of the resin are resin acid, α- and β-guaiaconic acids (about 70 per cent.), guaiaretic acid (about 11 per cent.), and a small proportion of guaiacic acid; α-guaiaconic acid is colourless and amorphous, β-guaiaconic acid is colourless and crystalline, guaiaretic acid is light brown and amorphous. The resin also contains guaiac-β-resin (15 per cent.) and small quantities of guaiac-yellow, vanillin, and guaiacsaponin. Guaiaconic acid is readily converted by oxidising agents (ferric chloride, ozone, hydrogen peroxide, chromic acid, etc.) into a deep blue substance termed guaiac-blue.
Action and Uses.—Guaiacum resin is a mild laxative and diuretic. For its supposed action upon the mucous membranes of the throat, it is used in the form of lozenge and pastille (see Trochisci Gualaci). In acute tonsillitis it is given in powder form or as Mistura Guaiaci. Guaiacum resin is employed in chronic rheumatism and gout; it sometimes relieves the pain and inflammation, and if taken between the attacks may lessen the tendency to recurrence. It is said to be of some service in dysmenorrhoea, 6 decigrams (10 grains), three times daily. It can be administered in powder, cachets, or capsules. The ammoniated tincture of guaiacum is used in mixture form, and should be prescribed with mucilage of gum acacia (1 part in 8 parts of mixture) to suspend the resin. A simple tincture of guaiacum is employed with ozonic ether as a test for blood. Lozenges or cachets of guaiacum and sulphur are used in chronic rheumatism; Confectio Gualaci Composita is a domestic remedy used for a similar purpose.
Dose.—3 to 10 decigrams (5 to 15 grains).
- Confectio Guaiaci Composita, B.P.C.—COMPOUND CONFECTION OF GUAIACUM. Syn.—Chelsea Pensioner.
- Guaiacum resin, 1; rhubarb, 2; acid potassium tartrate, 7.5; nutmeg, 1; sublimed sulphur, 14.5; clarified honey, 74. A popular remedy for gout and rheumatism. Dose.—4 to 8 grammes (60 to 120 grains).
- Mistura Guaiaci, B.P.—GUAIACUM MIXTURE. Syn.—Lac Guaiaci; Emulsio Guaiaci.
- Guaiacum resin, 2.5; refined sugar, 2.5; tragacanth, in powder, 0.4; cinnamon water, 100. Powder the resin, add the sugar and tragacanth, mix thoroughly, then gradually add the cinnamon water, with constant trituration, and strain the mixture through muslin. Each fluid ounce contains about 11 grains of guaiacum resin. This mixture is employed in chronic gout and rheumatism, also in tonsillitis and some skin diseases. Dose.—15 to 30 mils (½ to 1 fluid ounce).
- Tinctura Guaiaci, U.S.P. and B.P.C.—TINCTURE OF GUAIACUM. Syn.—Tincture of Guaiac.
- Guaiacum resin, in powder, 20; alcohol, sufficient to produce 100. Mixtures containing tincture of guaiacum require the addition of one-eighth of their bulk of mucilage of gum acacia to suspend the resin in a diffusible form. It is used with ozonic ether as a test for blood; if a few drops of the tincture be added to the suspected liquid, followed by a few drops of ozonic ether, a deep blue colour is developed if blood be present. Dose.—2 to 4 mils (½ to 1 fluid drachm).
- Tinctura Guaiaci Ammoniata, B.P.—AMMONIATED TINCTURE OF GUAIACUM.
- Guaiacum resin, in powder, 20; oil of nutmeg, 0.31; Oil of lemon, 0.21; strong solution of ammonia, 7.5; alcohol, sufficient to produce 100. Macerate the resin in the solution of ammonia and 80 of alcohol for forty-eight hours, with frequent agitation; then filter, dissolve the oils in the filtrate, and pass sufficient alcohol through the filter to make up to the required volume. Mixtures containing ammoniated tincture of guaiacum require the addition of one-eighth of their bulk of mucilage of gum acacia to suspend the resin in a diffusible form; the mucilage should be diluted with three or four times its bulk of water, and the tincture—measured in a dry measure—added in successive portions, shaking after each addition. Its use is empirical in chronic rheumatism, rheumatoid arthritis, and syphilis. Dose.—2 to 4 mils (½ to 1 fluid drachm).
- Tinctura Guaiaci Ammoniata, U.S.P.—AMMONIATED TINCTURE OF GUAIAC.
- Guaiac, in No. 40 powder, 20; aromatic spirit of ammonia, sufficient to produce 100. Average dose.—2 mils (30 minims).
- Trochiscus Guaiaci Resinae, B.P.—GUAIACUM RESIN LOZENGE.
- Each lozenge contains guaiacum resin, 3 grains; with fruit basis. Guaiacum resin lozenges are used in chronic tonsillitis and pharyngitis, especially when these conditions are associated with rheumatism. Dose.—1 to 6 lozenges.